Question, If you take a full keg of beer and hit it with 30 lbs. of CO2 and then disconnect it for a few days the CO2 will be absorbed into the beer but should the pressure in the keg drop or will the pressure stay at 30?

Iíve been fighting a leaking keg and thought I had it fixed after replacing a post but now Iím not too sure.

The pressure is going to equalize between the head space and the beer. So, no, it shouldn't stay at 30 psi in the head space.

__________________
Of all tyrannies, a tyranny sincerely exercised for the good of its victims may be the most oppressive. It would be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated; but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience. - C. S. Lewis, English essayist & juvenile novelist (1898 - 1963)

More specifically, the head space is typically about 1/10th the volume of the whole keg. If you put 30psi into the head space and quickly disconnect, in about a day the equilized pressure in both the headspace and beer with be about 3 PSI. If you look at the charts, you'll quickly see why you can't practically do a single application of gas to reach say 2.5 volumes. A chart pressure of 13 psi would require a single burst of 130psi which is where your keg's pressure limit sits.